1 /* 2 * xfrm6_policy.c: based on xfrm4_policy.c 3 * 4 * Authors: 5 * Mitsuru KANDA @USAGI 6 * Kazunori MIYAZAWA @USAGI 7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 8 * IPv6 support 9 * YOSHIFUJI Hideaki 10 * Split up af-specific portion 11 * 12 */ 13 14 #include <asm/bug.h> 15 #include <linux/compiler.h> 16 #include <linux/config.h> 17 #include <linux/netdevice.h> 18 #include <net/addrconf.h> 19 #include <net/xfrm.h> 20 #include <net/ip.h> 21 #include <net/ipv6.h> 22 #include <net/ip6_route.h> 23 24 static struct dst_ops xfrm6_dst_ops; 25 static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 26 27 static struct xfrm_type_map xfrm6_type_map = { .lock = RW_LOCK_UNLOCKED }; 28 29 static int xfrm6_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) 30 { 31 int err = 0; 32 *dst = (struct xfrm_dst*)ip6_route_output(NULL, fl); 33 if (!*dst) 34 err = -ENETUNREACH; 35 return err; 36 } 37 38 static struct dst_entry * 39 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy) 40 { 41 struct dst_entry *dst; 42 43 /* Still not clear if we should set fl->fl6_{src,dst}... */ 44 read_lock_bh(&policy->lock); 45 for (dst = policy->bundles; dst; dst = dst->next) { 46 struct xfrm_dst *xdst = (struct xfrm_dst*)dst; 47 struct in6_addr fl_dst_prefix, fl_src_prefix; 48 49 ipv6_addr_prefix(&fl_dst_prefix, 50 &fl->fl6_dst, 51 xdst->u.rt6.rt6i_dst.plen); 52 ipv6_addr_prefix(&fl_src_prefix, 53 &fl->fl6_src, 54 xdst->u.rt6.rt6i_src.plen); 55 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) && 56 ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) && 57 xfrm_bundle_ok(xdst, fl, AF_INET6)) { 58 dst_clone(dst); 59 break; 60 } 61 } 62 read_unlock_bh(&policy->lock); 63 return dst; 64 } 65 66 /* Allocate chain of dst_entry's, attach known xfrm's, calculate 67 * all the metrics... Shortly, bundle a bundle. 68 */ 69 70 static int 71 __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, 72 struct flowi *fl, struct dst_entry **dst_p) 73 { 74 struct dst_entry *dst, *dst_prev; 75 struct rt6_info *rt0 = (struct rt6_info*)(*dst_p); 76 struct rt6_info *rt = rt0; 77 struct in6_addr *remote = &fl->fl6_dst; 78 struct in6_addr *local = &fl->fl6_src; 79 struct flowi fl_tunnel = { 80 .nl_u = { 81 .ip6_u = { 82 .saddr = *local, 83 .daddr = *remote 84 } 85 } 86 }; 87 int i; 88 int err = 0; 89 int header_len = 0; 90 int trailer_len = 0; 91 92 dst = dst_prev = NULL; 93 dst_hold(&rt->u.dst); 94 95 for (i = 0; i < nx; i++) { 96 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops); 97 struct xfrm_dst *xdst; 98 int tunnel = 0; 99 100 if (unlikely(dst1 == NULL)) { 101 err = -ENOBUFS; 102 dst_release(&rt->u.dst); 103 goto error; 104 } 105 106 if (!dst) 107 dst = dst1; 108 else { 109 dst_prev->child = dst1; 110 dst1->flags |= DST_NOHASH; 111 dst_clone(dst1); 112 } 113 114 xdst = (struct xfrm_dst *)dst1; 115 xdst->route = &rt->u.dst; 116 117 dst1->next = dst_prev; 118 dst_prev = dst1; 119 if (xfrm[i]->props.mode) { 120 remote = (struct in6_addr*)&xfrm[i]->id.daddr; 121 local = (struct in6_addr*)&xfrm[i]->props.saddr; 122 tunnel = 1; 123 } 124 header_len += xfrm[i]->props.header_len; 125 trailer_len += xfrm[i]->props.trailer_len; 126 127 if (tunnel) { 128 ipv6_addr_copy(&fl_tunnel.fl6_dst, remote); 129 ipv6_addr_copy(&fl_tunnel.fl6_src, local); 130 err = xfrm_dst_lookup((struct xfrm_dst **) &rt, 131 &fl_tunnel, AF_INET6); 132 if (err) 133 goto error; 134 } else 135 dst_hold(&rt->u.dst); 136 } 137 138 dst_prev->child = &rt->u.dst; 139 dst->path = &rt->u.dst; 140 141 *dst_p = dst; 142 dst = dst_prev; 143 144 dst_prev = *dst_p; 145 i = 0; 146 for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { 147 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; 148 149 dst_prev->xfrm = xfrm[i++]; 150 dst_prev->dev = rt->u.dst.dev; 151 if (rt->u.dst.dev) 152 dev_hold(rt->u.dst.dev); 153 dst_prev->obsolete = -1; 154 dst_prev->flags |= DST_HOST; 155 dst_prev->lastuse = jiffies; 156 dst_prev->header_len = header_len; 157 dst_prev->trailer_len = trailer_len; 158 memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); 159 160 /* Copy neighbour for reachability confirmation */ 161 dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); 162 dst_prev->input = rt->u.dst.input; 163 dst_prev->output = xfrm6_output; 164 /* Sheit... I remember I did this right. Apparently, 165 * it was magically lost, so this code needs audit */ 166 x->u.rt6.rt6i_flags = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); 167 x->u.rt6.rt6i_metric = rt0->rt6i_metric; 168 x->u.rt6.rt6i_node = rt0->rt6i_node; 169 x->u.rt6.rt6i_gateway = rt0->rt6i_gateway; 170 memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway)); 171 x->u.rt6.rt6i_dst = rt0->rt6i_dst; 172 x->u.rt6.rt6i_src = rt0->rt6i_src; 173 x->u.rt6.rt6i_idev = rt0->rt6i_idev; 174 in6_dev_hold(rt0->rt6i_idev); 175 header_len -= x->u.dst.xfrm->props.header_len; 176 trailer_len -= x->u.dst.xfrm->props.trailer_len; 177 } 178 179 xfrm_init_pmtu(dst); 180 return 0; 181 182 error: 183 if (dst) 184 dst_free(dst); 185 return err; 186 } 187 188 static inline void 189 _decode_session6(struct sk_buff *skb, struct flowi *fl) 190 { 191 u16 offset = sizeof(struct ipv6hdr); 192 struct ipv6hdr *hdr = skb->nh.ipv6h; 193 struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); 194 u8 nexthdr = skb->nh.ipv6h->nexthdr; 195 196 memset(fl, 0, sizeof(struct flowi)); 197 ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr); 198 ipv6_addr_copy(&fl->fl6_src, &hdr->saddr); 199 200 while (pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data)) { 201 switch (nexthdr) { 202 case NEXTHDR_ROUTING: 203 case NEXTHDR_HOP: 204 case NEXTHDR_DEST: 205 offset += ipv6_optlen(exthdr); 206 nexthdr = exthdr->nexthdr; 207 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset); 208 break; 209 210 case IPPROTO_UDP: 211 case IPPROTO_TCP: 212 case IPPROTO_SCTP: 213 if (pskb_may_pull(skb, skb->nh.raw + offset + 4 - skb->data)) { 214 u16 *ports = (u16 *)exthdr; 215 216 fl->fl_ip_sport = ports[0]; 217 fl->fl_ip_dport = ports[1]; 218 } 219 fl->proto = nexthdr; 220 return; 221 222 case IPPROTO_ICMPV6: 223 if (pskb_may_pull(skb, skb->nh.raw + offset + 2 - skb->data)) { 224 u8 *icmp = (u8 *)exthdr; 225 226 fl->fl_icmp_type = icmp[0]; 227 fl->fl_icmp_code = icmp[1]; 228 } 229 fl->proto = nexthdr; 230 return; 231 232 /* XXX Why are there these headers? */ 233 case IPPROTO_AH: 234 case IPPROTO_ESP: 235 case IPPROTO_COMP: 236 default: 237 fl->fl_ipsec_spi = 0; 238 fl->proto = nexthdr; 239 return; 240 }; 241 } 242 } 243 244 static inline int xfrm6_garbage_collect(void) 245 { 246 read_lock(&xfrm6_policy_afinfo.lock); 247 xfrm6_policy_afinfo.garbage_collect(); 248 read_unlock(&xfrm6_policy_afinfo.lock); 249 return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2); 250 } 251 252 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) 253 { 254 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 255 struct dst_entry *path = xdst->route; 256 257 path->ops->update_pmtu(path, mtu); 258 } 259 260 static void xfrm6_dst_destroy(struct dst_entry *dst) 261 { 262 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 263 264 if (likely(xdst->u.rt6.rt6i_idev)) 265 in6_dev_put(xdst->u.rt6.rt6i_idev); 266 xfrm_dst_destroy(xdst); 267 } 268 269 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 270 int unregister) 271 { 272 struct xfrm_dst *xdst; 273 274 if (!unregister) 275 return; 276 277 xdst = (struct xfrm_dst *)dst; 278 if (xdst->u.rt6.rt6i_idev->dev == dev) { 279 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev); 280 BUG_ON(!loopback_idev); 281 282 do { 283 in6_dev_put(xdst->u.rt6.rt6i_idev); 284 xdst->u.rt6.rt6i_idev = loopback_idev; 285 in6_dev_hold(loopback_idev); 286 xdst = (struct xfrm_dst *)xdst->u.dst.child; 287 } while (xdst->u.dst.xfrm); 288 289 __in6_dev_put(loopback_idev); 290 } 291 292 xfrm_dst_ifdown(dst, dev); 293 } 294 295 static struct dst_ops xfrm6_dst_ops = { 296 .family = AF_INET6, 297 .protocol = __constant_htons(ETH_P_IPV6), 298 .gc = xfrm6_garbage_collect, 299 .update_pmtu = xfrm6_update_pmtu, 300 .destroy = xfrm6_dst_destroy, 301 .ifdown = xfrm6_dst_ifdown, 302 .gc_thresh = 1024, 303 .entry_size = sizeof(struct xfrm_dst), 304 }; 305 306 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 307 .family = AF_INET6, 308 .lock = RW_LOCK_UNLOCKED, 309 .type_map = &xfrm6_type_map, 310 .dst_ops = &xfrm6_dst_ops, 311 .dst_lookup = xfrm6_dst_lookup, 312 .find_bundle = __xfrm6_find_bundle, 313 .bundle_create = __xfrm6_bundle_create, 314 .decode_session = _decode_session6, 315 }; 316 317 static void __init xfrm6_policy_init(void) 318 { 319 xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 320 } 321 322 static void xfrm6_policy_fini(void) 323 { 324 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 325 } 326 327 void __init xfrm6_init(void) 328 { 329 xfrm6_policy_init(); 330 xfrm6_state_init(); 331 } 332 333 void xfrm6_fini(void) 334 { 335 //xfrm6_input_fini(); 336 xfrm6_policy_fini(); 337 xfrm6_state_fini(); 338 } 339